![Kirill Smelkov](/assets/img/avatar_default.png)
Using scripts/coccinelle/api/stream_open.cocci added in10dce8af34
("fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock"), search and convert to stream_open all in-kernel nonseekable_open users for which read and write actually do not depend on ppos and where there is no other methods in file_operations which assume @offset access. I've verified each generated change manually - that it is correct to convert - and each other nonseekable_open instance left - that it is either not correct to convert there, or that it is not converted due to current stream_open.cocci limitations. The script also does not convert files that should be valid to convert, but that currently have .llseek = noop_llseek or generic_file_llseek for unknown reason despite file being opened with nonseekable_open (e.g. drivers/input/mousedev.c) Among cases converted 14 were potentially vulnerable to read vs write deadlock (see details in10dce8af34
): drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/infiniband/core/user_mad.c:988:1-17: ERROR: umad_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/input/misc/uinput.c:401:1-17: ERROR: uinput_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. and the rest were just safe to convert to stream_open because their read and write do not use ppos at all and corresponding file_operations do not have methods that assume @offset file access(*): arch/powerpc/platforms/52xx/mpc52xx_gpt.c:631:8-24: WARNING: mpc52xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_ibox_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_ibox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_mbox_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_mbox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_wbox_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_wbox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/um/drivers/harddog_kern.c:88:8-24: WARNING: harddog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. arch/x86/kernel/cpu/microcode/core.c:430:33-49: WARNING: microcode_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/ds1620.c:215:8-24: WARNING: ds1620_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/dtlk.c:301:1-17: WARNING: dtlk_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/ipmi/ipmi_watchdog.c:840:9-25: WARNING: ipmi_wdog_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/pcmcia/scr24x_cs.c:95:8-24: WARNING: scr24x_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/tb0219.c:246:9-25: WARNING: tb0219_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/firewire/nosy.c:306:8-24: WARNING: nosy_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/hwmon/fschmd.c:840:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/hwmon/w83793.c:1344:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/infiniband/core/ucma.c:1747:8-24: WARNING: ucma_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/infiniband/core/ucm.c:1178:8-24: WARNING: ucm_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/infiniband/core/uverbs_main.c:1086:8-24: WARNING: uverbs_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/input/joydev.c:282:1-17: WARNING: joydev_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/pci/switch/switchtec.c:393:1-17: WARNING: switchtec_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/platform/chrome/cros_ec_debugfs.c:135:8-24: WARNING: cros_ec_console_log_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/rtc/rtc-ds1374.c:470:9-25: WARNING: ds1374_wdt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/rtc/rtc-m41t80.c:805:9-25: WARNING: wdt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/s390/char/tape_char.c:293:2-18: WARNING: tape_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/s390/char/zcore.c:194:8-24: WARNING: zcore_reipl_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/s390/crypto/zcrypt_api.c:528:8-24: WARNING: zcrypt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/spi/spidev.c:594:1-17: WARNING: spidev_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/staging/pi433/pi433_if.c:974:1-17: WARNING: pi433_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/acquirewdt.c:203:8-24: WARNING: acq_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/advantechwdt.c:202:8-24: WARNING: advwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/alim1535_wdt.c:252:8-24: WARNING: ali_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/alim7101_wdt.c:217:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ar7_wdt.c:166:8-24: WARNING: ar7_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/at91rm9200_wdt.c:113:8-24: WARNING: at91wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ath79_wdt.c:135:8-24: WARNING: ath79_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/bcm63xx_wdt.c:119:8-24: WARNING: bcm63xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/cpu5wdt.c:143:8-24: WARNING: cpu5wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/cpwd.c:397:8-24: WARNING: cpwd_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/eurotechwdt.c:319:8-24: WARNING: eurwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/f71808e_wdt.c:528:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/gef_wdt.c:232:8-24: WARNING: gef_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/geodewdt.c:95:8-24: WARNING: geodewdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ib700wdt.c:241:8-24: WARNING: ibwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ibmasr.c:326:8-24: WARNING: asr_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/indydog.c:80:8-24: WARNING: indydog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/intel_scu_watchdog.c:307:8-24: WARNING: intel_scu_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/iop_wdt.c:104:8-24: WARNING: iop_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/it8712f_wdt.c:330:8-24: WARNING: it8712f_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ixp4xx_wdt.c:68:8-24: WARNING: ixp4xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ks8695_wdt.c:145:8-24: WARNING: ks8695wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/m54xx_wdt.c:88:8-24: WARNING: m54xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/machzwd.c:336:8-24: WARNING: zf_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/mixcomwd.c:153:8-24: WARNING: mixcomwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/mtx-1_wdt.c:121:8-24: WARNING: mtx1_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/mv64x60_wdt.c:136:8-24: WARNING: mv64x60_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/nuc900_wdt.c:134:8-24: WARNING: nuc900wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/nv_tco.c:164:8-24: WARNING: nv_tco_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pc87413_wdt.c:289:8-24: WARNING: pc87413_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd.c:698:8-24: WARNING: pcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd.c:737:8-24: WARNING: pcwd_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_pci.c:581:8-24: WARNING: pcipcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_pci.c:623:8-24: WARNING: pcipcwd_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_usb.c:488:8-24: WARNING: usb_pcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_usb.c:527:8-24: WARNING: usb_pcwd_temperature_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pika_wdt.c:121:8-24: WARNING: pikawdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pnx833x_wdt.c:119:8-24: WARNING: pnx833x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/rc32434_wdt.c:153:8-24: WARNING: rc32434_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/rdc321x_wdt.c:145:8-24: WARNING: rdc321x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/riowd.c:79:1-17: WARNING: riowd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sa1100_wdt.c:62:8-24: WARNING: sa1100dog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc60xxwdt.c:211:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc7240_wdt.c:139:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc8360.c:274:8-24: WARNING: sbc8360_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc_epx_c3.c:81:8-24: WARNING: epx_c3_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc_fitpc2_wdt.c:78:8-24: WARNING: fitpc2_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sb_wdog.c:108:1-17: WARNING: sbwdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sc1200wdt.c:181:8-24: WARNING: sc1200wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sc520_wdt.c:261:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sch311x_wdt.c:319:8-24: WARNING: sch311x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/scx200_wdt.c:105:8-24: WARNING: scx200_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/smsc37b787_wdt.c:369:8-24: WARNING: wb_smsc_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/w83877f_wdt.c:227:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/w83977f_wdt.c:301:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wafer5823wdt.c:200:8-24: WARNING: wafwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/watchdog_dev.c:828:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdrtas.c:379:8-24: WARNING: wdrtas_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdrtas.c:445:8-24: WARNING: wdrtas_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt285.c:104:1-17: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt977.c:276:8-24: WARNING: wdt977_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt.c:424:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt.c:484:8-24: WARNING: wdt_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt_pci.c:464:8-24: WARNING: wdtpci_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt_pci.c:527:8-24: WARNING: wdtpci_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. net/batman-adv/log.c:105:1-17: WARNING: batadv_log_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. sound/core/control.c:57:7-23: WARNING: snd_ctl_f_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. sound/core/rawmidi.c:385:7-23: WARNING: snd_rawmidi_f_ops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. sound/core/seq/seq_clientmgr.c:310:7-23: WARNING: snd_seq_f_ops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. sound/core/timer.c:1428:7-23: WARNING: snd_timer_f_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. One can also recheck/review the patch via generating it with explanation comments included via $ make coccicheck MODE=patch COCCI=scripts/coccinelle/api/stream_open.cocci SPFLAGS="-D explain" (*) This second group also contains cases with read/write deadlocks that stream_open.cocci don't yet detect, but which are still valid to convert to stream_open since ppos is not used. For example drivers/pci/switch/switchtec.c calls wait_for_completion_interruptible() in its .read, but stream_open.cocci currently detects only "wait_event*" as blocking. Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yongzhi Pan <panyongzhi@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Juergen Gross <jgross@suse.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Tejun Heo <tj@kernel.org> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Nikolaus Rath <Nikolaus@rath.org> Cc: Han-Wen Nienhuys <hanwen@google.com> Cc: Anatolij Gustschin <agust@denx.de> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James R. Van Zandt" <jrv@vanzandt.mv.com> Cc: Corey Minyard <minyard@acm.org> Cc: Harald Welte <laforge@gnumonks.org> Acked-by: Lubomir Rintel <lkundrak@v3.sk> [scr24x_cs] Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Johan Hovold <johan@kernel.org> Cc: David Herrmann <dh.herrmann@googlemail.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com> Cc: Jean Delvare <jdelvare@suse.com> Acked-by: Guenter Roeck <linux@roeck-us.net> [watchdog/* hwmon/*] Cc: Rudolf Marek <r.marek@assembler.cz> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Kurt Schwemmer <kurt.schwemmer@microsemi.com> Acked-by: Logan Gunthorpe <logang@deltatee.com> [drivers/pci/switch/switchtec] Acked-by: Bjorn Helgaas <bhelgaas@google.com> [drivers/pci/switch/switchtec] Cc: Benson Leung <bleung@chromium.org> Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> [platform/chrome] Cc: Alessandro Zummo <a.zummo@towertech.it> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> [rtc/*] Cc: Mark Brown <broonie@kernel.org> Cc: Wim Van Sebroeck <wim@linux-watchdog.org> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: Wan ZongShun <mcuos.com@gmail.com> Cc: Zwane Mwaikambo <zwanem@gmail.com> Cc: Marek Lindner <mareklindner@neomailbox.ch> Cc: Simon Wunderlich <sw@simonwunderlich.de> Cc: Antonio Quartulli <a@unstable.cc> Cc: "David S. Miller" <davem@davemloft.net> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
435 lines
11 KiB
C
435 lines
11 KiB
C
/*
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* AMD Elan SC520 processor Watchdog Timer driver
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*
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* Based on acquirewdt.c by Alan Cox,
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* and sbc60xxwdt.c by Jakob Oestergaard <jakob@unthought.net>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* The authors do NOT admit liability nor provide warranty for
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* any of this software. This material is provided "AS-IS" in
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* the hope that it may be useful for others.
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*
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* (c) Copyright 2001 Scott Jennings <linuxdrivers@oro.net>
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* 9/27 - 2001 [Initial release]
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*
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* Additional fixes Alan Cox
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* - Fixed formatting
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* - Removed debug printks
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* - Fixed SMP built kernel deadlock
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* - Switched to private locks not lock_kernel
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* - Used ioremap/writew/readw
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* - Added NOWAYOUT support
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* 4/12 - 2002 Changes by Rob Radez <rob@osinvestor.com>
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* - Change comments
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* - Eliminate fop_llseek
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* - Change CONFIG_WATCHDOG_NOWAYOUT semantics
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* - Add KERN_* tags to printks
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* - fix possible wdt_is_open race
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* - Report proper capabilities in watchdog_info
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* - Add WDIOC_{GETSTATUS, GETBOOTSTATUS, SETTIMEOUT,
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* GETTIMEOUT, SETOPTIONS} ioctls
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* 09/8 - 2003 Changes by Wim Van Sebroeck <wim@iguana.be>
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* - cleanup of trailing spaces
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* - added extra printk's for startup problems
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* - use module_param
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* - made timeout (the emulated heartbeat) a module_param
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* - made the keepalive ping an internal subroutine
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* 3/27 - 2004 Changes by Sean Young <sean@mess.org>
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* - set MMCR_BASE to 0xfffef000
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|
* - CBAR does not need to be read
|
|
* - removed debugging printks
|
|
*
|
|
* This WDT driver is different from most other Linux WDT
|
|
* drivers in that the driver will ping the watchdog by itself,
|
|
* because this particular WDT has a very short timeout (1.6
|
|
* seconds) and it would be insane to count on any userspace
|
|
* daemon always getting scheduled within that time frame.
|
|
*
|
|
* This driver uses memory mapped IO, and spinlock.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/types.h>
|
|
#include <linux/timer.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/watchdog.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/ioport.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/init.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/io.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
|
|
/*
|
|
* The AMD Elan SC520 timeout value is 492us times a power of 2 (0-7)
|
|
*
|
|
* 0: 492us 2: 1.01s 4: 4.03s 6: 16.22s
|
|
* 1: 503ms 3: 2.01s 5: 8.05s 7: 32.21s
|
|
*
|
|
* We will program the SC520 watchdog for a timeout of 2.01s.
|
|
* If we reset the watchdog every ~250ms we should be safe.
|
|
*/
|
|
|
|
#define WDT_INTERVAL (HZ/4+1)
|
|
|
|
/*
|
|
* We must not require too good response from the userspace daemon.
|
|
* Here we require the userspace daemon to send us a heartbeat
|
|
* char to /dev/watchdog every 30 seconds.
|
|
*/
|
|
|
|
#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
|
|
/* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
|
|
static int timeout = WATCHDOG_TIMEOUT;
|
|
module_param(timeout, int, 0);
|
|
MODULE_PARM_DESC(timeout,
|
|
"Watchdog timeout in seconds. (1 <= timeout <= 3600, default="
|
|
__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
|
|
|
|
static bool nowayout = WATCHDOG_NOWAYOUT;
|
|
module_param(nowayout, bool, 0);
|
|
MODULE_PARM_DESC(nowayout,
|
|
"Watchdog cannot be stopped once started (default="
|
|
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
|
|
|
|
/*
|
|
* AMD Elan SC520 - Watchdog Timer Registers
|
|
*/
|
|
#define MMCR_BASE 0xfffef000 /* The default base address */
|
|
#define OFFS_WDTMRCTL 0xCB0 /* Watchdog Timer Control Register */
|
|
|
|
/* WDT Control Register bit definitions */
|
|
#define WDT_EXP_SEL_01 0x0001 /* [01] Time-out = 496 us (with 33 Mhz clk). */
|
|
#define WDT_EXP_SEL_02 0x0002 /* [02] Time-out = 508 ms (with 33 Mhz clk). */
|
|
#define WDT_EXP_SEL_03 0x0004 /* [03] Time-out = 1.02 s (with 33 Mhz clk). */
|
|
#define WDT_EXP_SEL_04 0x0008 /* [04] Time-out = 2.03 s (with 33 Mhz clk). */
|
|
#define WDT_EXP_SEL_05 0x0010 /* [05] Time-out = 4.07 s (with 33 Mhz clk). */
|
|
#define WDT_EXP_SEL_06 0x0020 /* [06] Time-out = 8.13 s (with 33 Mhz clk). */
|
|
#define WDT_EXP_SEL_07 0x0040 /* [07] Time-out = 16.27s (with 33 Mhz clk). */
|
|
#define WDT_EXP_SEL_08 0x0080 /* [08] Time-out = 32.54s (with 33 Mhz clk). */
|
|
#define WDT_IRQ_FLG 0x1000 /* [12] Interrupt Request Flag */
|
|
#define WDT_WRST_ENB 0x4000 /* [14] Watchdog Timer Reset Enable */
|
|
#define WDT_ENB 0x8000 /* [15] Watchdog Timer Enable */
|
|
|
|
static __u16 __iomem *wdtmrctl;
|
|
|
|
static void wdt_timer_ping(struct timer_list *);
|
|
static DEFINE_TIMER(timer, wdt_timer_ping);
|
|
static unsigned long next_heartbeat;
|
|
static unsigned long wdt_is_open;
|
|
static char wdt_expect_close;
|
|
static DEFINE_SPINLOCK(wdt_spinlock);
|
|
|
|
/*
|
|
* Whack the dog
|
|
*/
|
|
|
|
static void wdt_timer_ping(struct timer_list *unused)
|
|
{
|
|
/* If we got a heartbeat pulse within the WDT_US_INTERVAL
|
|
* we agree to ping the WDT
|
|
*/
|
|
if (time_before(jiffies, next_heartbeat)) {
|
|
/* Ping the WDT */
|
|
spin_lock(&wdt_spinlock);
|
|
writew(0xAAAA, wdtmrctl);
|
|
writew(0x5555, wdtmrctl);
|
|
spin_unlock(&wdt_spinlock);
|
|
|
|
/* Re-set the timer interval */
|
|
mod_timer(&timer, jiffies + WDT_INTERVAL);
|
|
} else
|
|
pr_warn("Heartbeat lost! Will not ping the watchdog\n");
|
|
}
|
|
|
|
/*
|
|
* Utility routines
|
|
*/
|
|
|
|
static void wdt_config(int writeval)
|
|
{
|
|
unsigned long flags;
|
|
|
|
/* buy some time (ping) */
|
|
spin_lock_irqsave(&wdt_spinlock, flags);
|
|
readw(wdtmrctl); /* ensure write synchronization */
|
|
writew(0xAAAA, wdtmrctl);
|
|
writew(0x5555, wdtmrctl);
|
|
/* unlock WDT = make WDT configuration register writable one time */
|
|
writew(0x3333, wdtmrctl);
|
|
writew(0xCCCC, wdtmrctl);
|
|
/* write WDT configuration register */
|
|
writew(writeval, wdtmrctl);
|
|
spin_unlock_irqrestore(&wdt_spinlock, flags);
|
|
}
|
|
|
|
static int wdt_startup(void)
|
|
{
|
|
next_heartbeat = jiffies + (timeout * HZ);
|
|
|
|
/* Start the timer */
|
|
mod_timer(&timer, jiffies + WDT_INTERVAL);
|
|
|
|
/* Start the watchdog */
|
|
wdt_config(WDT_ENB | WDT_WRST_ENB | WDT_EXP_SEL_04);
|
|
|
|
pr_info("Watchdog timer is now enabled\n");
|
|
return 0;
|
|
}
|
|
|
|
static int wdt_turnoff(void)
|
|
{
|
|
/* Stop the timer */
|
|
del_timer(&timer);
|
|
|
|
/* Stop the watchdog */
|
|
wdt_config(0);
|
|
|
|
pr_info("Watchdog timer is now disabled...\n");
|
|
return 0;
|
|
}
|
|
|
|
static int wdt_keepalive(void)
|
|
{
|
|
/* user land ping */
|
|
next_heartbeat = jiffies + (timeout * HZ);
|
|
return 0;
|
|
}
|
|
|
|
static int wdt_set_heartbeat(int t)
|
|
{
|
|
if ((t < 1) || (t > 3600)) /* arbitrary upper limit */
|
|
return -EINVAL;
|
|
|
|
timeout = t;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* /dev/watchdog handling
|
|
*/
|
|
|
|
static ssize_t fop_write(struct file *file, const char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
/* See if we got the magic character 'V' and reload the timer */
|
|
if (count) {
|
|
if (!nowayout) {
|
|
size_t ofs;
|
|
|
|
/* note: just in case someone wrote the magic character
|
|
* five months ago... */
|
|
wdt_expect_close = 0;
|
|
|
|
/* now scan */
|
|
for (ofs = 0; ofs != count; ofs++) {
|
|
char c;
|
|
if (get_user(c, buf + ofs))
|
|
return -EFAULT;
|
|
if (c == 'V')
|
|
wdt_expect_close = 42;
|
|
}
|
|
}
|
|
|
|
/* Well, anyhow someone wrote to us, we should
|
|
return that favour */
|
|
wdt_keepalive();
|
|
}
|
|
return count;
|
|
}
|
|
|
|
static int fop_open(struct inode *inode, struct file *file)
|
|
{
|
|
/* Just in case we're already talking to someone... */
|
|
if (test_and_set_bit(0, &wdt_is_open))
|
|
return -EBUSY;
|
|
if (nowayout)
|
|
__module_get(THIS_MODULE);
|
|
|
|
/* Good, fire up the show */
|
|
wdt_startup();
|
|
return stream_open(inode, file);
|
|
}
|
|
|
|
static int fop_close(struct inode *inode, struct file *file)
|
|
{
|
|
if (wdt_expect_close == 42)
|
|
wdt_turnoff();
|
|
else {
|
|
pr_crit("Unexpected close, not stopping watchdog!\n");
|
|
wdt_keepalive();
|
|
}
|
|
clear_bit(0, &wdt_is_open);
|
|
wdt_expect_close = 0;
|
|
return 0;
|
|
}
|
|
|
|
static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|
{
|
|
void __user *argp = (void __user *)arg;
|
|
int __user *p = argp;
|
|
static const struct watchdog_info ident = {
|
|
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
|
|
| WDIOF_MAGICCLOSE,
|
|
.firmware_version = 1,
|
|
.identity = "SC520",
|
|
};
|
|
|
|
switch (cmd) {
|
|
case WDIOC_GETSUPPORT:
|
|
return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
|
|
case WDIOC_GETSTATUS:
|
|
case WDIOC_GETBOOTSTATUS:
|
|
return put_user(0, p);
|
|
case WDIOC_SETOPTIONS:
|
|
{
|
|
int new_options, retval = -EINVAL;
|
|
|
|
if (get_user(new_options, p))
|
|
return -EFAULT;
|
|
|
|
if (new_options & WDIOS_DISABLECARD) {
|
|
wdt_turnoff();
|
|
retval = 0;
|
|
}
|
|
|
|
if (new_options & WDIOS_ENABLECARD) {
|
|
wdt_startup();
|
|
retval = 0;
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
case WDIOC_KEEPALIVE:
|
|
wdt_keepalive();
|
|
return 0;
|
|
case WDIOC_SETTIMEOUT:
|
|
{
|
|
int new_timeout;
|
|
|
|
if (get_user(new_timeout, p))
|
|
return -EFAULT;
|
|
|
|
if (wdt_set_heartbeat(new_timeout))
|
|
return -EINVAL;
|
|
|
|
wdt_keepalive();
|
|
}
|
|
/* Fall through */
|
|
case WDIOC_GETTIMEOUT:
|
|
return put_user(timeout, p);
|
|
default:
|
|
return -ENOTTY;
|
|
}
|
|
}
|
|
|
|
static const struct file_operations wdt_fops = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.write = fop_write,
|
|
.open = fop_open,
|
|
.release = fop_close,
|
|
.unlocked_ioctl = fop_ioctl,
|
|
};
|
|
|
|
static struct miscdevice wdt_miscdev = {
|
|
.minor = WATCHDOG_MINOR,
|
|
.name = "watchdog",
|
|
.fops = &wdt_fops,
|
|
};
|
|
|
|
/*
|
|
* Notifier for system down
|
|
*/
|
|
|
|
static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
|
|
void *unused)
|
|
{
|
|
if (code == SYS_DOWN || code == SYS_HALT)
|
|
wdt_turnoff();
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
/*
|
|
* The WDT needs to learn about soft shutdowns in order to
|
|
* turn the timebomb registers off.
|
|
*/
|
|
|
|
static struct notifier_block wdt_notifier = {
|
|
.notifier_call = wdt_notify_sys,
|
|
};
|
|
|
|
static void __exit sc520_wdt_unload(void)
|
|
{
|
|
if (!nowayout)
|
|
wdt_turnoff();
|
|
|
|
/* Deregister */
|
|
misc_deregister(&wdt_miscdev);
|
|
unregister_reboot_notifier(&wdt_notifier);
|
|
iounmap(wdtmrctl);
|
|
}
|
|
|
|
static int __init sc520_wdt_init(void)
|
|
{
|
|
int rc = -EBUSY;
|
|
|
|
/* Check that the timeout value is within it's range ;
|
|
if not reset to the default */
|
|
if (wdt_set_heartbeat(timeout)) {
|
|
wdt_set_heartbeat(WATCHDOG_TIMEOUT);
|
|
pr_info("timeout value must be 1 <= timeout <= 3600, using %d\n",
|
|
WATCHDOG_TIMEOUT);
|
|
}
|
|
|
|
wdtmrctl = ioremap(MMCR_BASE + OFFS_WDTMRCTL, 2);
|
|
if (!wdtmrctl) {
|
|
pr_err("Unable to remap memory\n");
|
|
rc = -ENOMEM;
|
|
goto err_out_region2;
|
|
}
|
|
|
|
rc = register_reboot_notifier(&wdt_notifier);
|
|
if (rc) {
|
|
pr_err("cannot register reboot notifier (err=%d)\n", rc);
|
|
goto err_out_ioremap;
|
|
}
|
|
|
|
rc = misc_register(&wdt_miscdev);
|
|
if (rc) {
|
|
pr_err("cannot register miscdev on minor=%d (err=%d)\n",
|
|
WATCHDOG_MINOR, rc);
|
|
goto err_out_notifier;
|
|
}
|
|
|
|
pr_info("WDT driver for SC520 initialised. timeout=%d sec (nowayout=%d)\n",
|
|
timeout, nowayout);
|
|
|
|
return 0;
|
|
|
|
err_out_notifier:
|
|
unregister_reboot_notifier(&wdt_notifier);
|
|
err_out_ioremap:
|
|
iounmap(wdtmrctl);
|
|
err_out_region2:
|
|
return rc;
|
|
}
|
|
|
|
module_init(sc520_wdt_init);
|
|
module_exit(sc520_wdt_unload);
|
|
|
|
MODULE_AUTHOR("Scott and Bill Jennings");
|
|
MODULE_DESCRIPTION(
|
|
"Driver for watchdog timer in AMD \"Elan\" SC520 uProcessor");
|
|
MODULE_LICENSE("GPL");
|